In oilfield operations, reciprocating pumps are used for different applications such as fracturing subterranean formations to drill for oil or natural gas, cementing the wellbore, or treating the wellbore and/or formation. A reciprocating pump designed for fracturing operations is sometimes referred to as a “frac pump.” A reciprocating pump typically includes a power end and a fluid end (sometimes referred to as a cylindrical section). The fluid end is typically formed of a one piece construction or a series of blocks secured together by rods. The fluid end includes a fluid cylinder having a plunger passage for receiving a plunger or plunger throw, an inlet passage, and an outlet passage. Reciprocating pumps are oftentimes operated at pressures of 10,000 pounds per square inch (psi) and upward to 25,000 psi and at rates of up to 1,000 strokes per minute or even higher during fracturing operations.
During operation of a reciprocating pump, a fluid is pumped into the fluid cylinder through the inlet passage and out of the pump through the outlet passage. The inlet and outlet passages each include a valve assembly, which is typically opened by differential pressure of fluid and allows the fluid to flow in only one direction. A crossbore formed between the intersection of the plunger passage and the inlet and outlet passages forms a crossbore section that enables fluid to flow through the fluid cylinder. The crossbore configuration must be robust enough to handle the fluid that passes through the fluid cylinder. The fluid often contains solid particulates and/or corrosive material that can cause corrosion, erosion, and/or pitting on surfaces of the valve assembly, the passages, and/or the crossbore over time.
Typically, the crossbores of fluid cylinders are formed using a machining process and thereafter the crossbore section is manually hand blended to remove sharp edges from the machining process. The manual hand blending process takes time and requires labor. Moreover, the manual hand blending process is not consistent across all areas of the crossbore section, can vary with every fluid cylinder, and is not representative of three-dimensional design models used for finite element analysis (FEA) and autofrettage analysis. Consequently, the manual hand blending process can create a crossbore section with different stress points, which can result in inconsistent stresses along the crossbore section. Over time, the constant flow of the abrasive fluid mixture through the pump can erode and wear down the interior surfaces and/or internal components (e.g., valves, seats, springs, etc.) of the fluid cylinder, which can eventually cause the fluid cylinder to fail. Failure of the fluid cylinder of a reciprocating pump can have relatively devastating repercussions and/or can be relatively costly.